Searching \ for '[OT] Speed-of-light experiments give baffling resu' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/index.htm?key=speed+light+experiments
Search entire site for: 'Speed-of-light experiments give baffling resu'.

Exact match. Not showing close matches.
PICList Thread
'[OT] Speed-of-light experiments give baffling resu'
2011\09\22@160254 by Carey Fisher

face picon face
This MAY be really important!!!  If validated, a major part of physics will
have to be re-thought.  It would be fascinating to see such a change in my
lifetime.

*http://www.bbc.co.uk/news/science-environment-15017484*

Carey Fisher
Chief Technical Officer
New Communications Solutions, LLC
678-999-3956
spam_OUTcareyfisherTakeThisOuTspamncsradio.co

2011\09\22@163838 by Chris McSweeny

picon face
Those *s don't help with the URL, try:
http://www.bbc.co.uk/news/science-environment-15017484

On Thu, Sep 22, 2011 at 9:02 PM, Carey Fisher <.....careyfisherKILLspamspam@spam@ncsradio.com> wrote:
{Quote hidden}

>

2011\09\22@164814 by Joe Wronski

flavicon
face
Using  less than and greater than ('<' , '>') around URLs helps them not get broken up by mail programs, and they do not break the links.
Joe W


On 9/22/2011 4:38 PM, Chris McSweeny wrote:
{Quote hidden}

>> -

2011\09\22@165119 by Chris Roper

picon face
Or in the case of this link <>C? :

2011\09\22@183046 by IVP

face picon face
> http://www.bbc.co.uk/news/science-environment-15017484

I think the neutrinos just get excited by a trip to Italy

The figure I've seen is 20ppm faster than light. They allegedly
arrived 60ns before light would have, with an accountable
error of 10ns

One scientist asked why neutrinos haven't been observed (for
whatever reason) ahead of supernovae, which they should do
by a significant time period if at least one flavour of neutrino is
20ppm faster than light

20ppm of 1 year is 10.5 minutes. Even 1ppm faster than light
would be 30s per lightyear distance

Jo

2011\09\22@184931 by RussellMc

face picon face
>> http://www.bbc.co.uk/news/science-environment-15017484

It doesn't violate anything we think we know if the Neutrinos have a
negative rest mass, as has been suggested long before now.

Quite what the meaning of negative rest mass is is TBD - especially
for a "particle" that never rests. Photons live in a timeless
continuum of eternal now. Negative rest mass neutrinos would live in
an eternal world of "where will I have put my keys".

           Russel

2011\09\23@091919 by John Ferrell

face
flavicon
face
Challenges to the theory that the speed of light is neither a maximum or a constant figure seem to pop up occasionally. The sources are reputable but I never hear anything that disproves the challenges. There is something about the question yet to be explained. The last time I tried to understand the challenge it was in regard to computing wave guide dimensions. I never quite grasp what is really going on. Maybe someone really smart will be able to solve the puzzle with this new piece.

If time and the speed of light are not constant but bear the same relationship as time domain and frequency domain, could it be that relationship of time and the speed of light have a constant relationship?

Never mind, I am babbling this morning, more coffee needed...

On 9/22/2011 4:02 PM, Carey Fisher wrote:
{Quote hidden}

-- John Ferrell W8CCW
  "Until one has loved an animal,
    part of their soul remains unawakened."

2011\09\23@094746 by smplx

flavicon
face


On Fri, 23 Sep 2011, IVP wrote:

{Quote hidden}

60ns measured between 2 points lets you plot one point on a curve. If you don't know what shape the curve is, assuming it's a straight line and looking for other points on that line isn't going to get you anywhere :-)

Regards
Sergio Masc

2011\09\23@095555 by Yigit Turgut

picon face
Yes, it doesn't violet anything because  classical and quantum physics
are defined by distinct features. Speed of light is the limit for the
macroscopic universe and general relativity obeys that as well. These
findings doesn't violate any component in our current understanding
but is surely a nice development. For subatomic world, speed of light
is not that fast. For example entanglement phenomena happens literally
simultaneously, doesn't matter how apart the entangled
particles/photons are ; projection of the interaction is instant.

On Fri, Sep 23, 2011 at 1:48 AM, RussellMc <@spam@apptechnzKILLspamspamgmail.com> wrote:
{Quote hidden}

>

2011\09\23@102356 by Isaac Marino Bavaresco

flavicon
face
Em 23/9/2011 10:48, smplx escreveu:
{Quote hidden}

The neutrinos traveled from Swiss to Italy inside rock (and perhaps
magma) in a straight line. For neutrinos that's easy.
In the 60ns the light travels approximately 18m.

My question is: Did they know the exact distance with a precision of a
few meters between two points separated by 732km? Both buried under
hundreds of meters of rock?

I'm sure they could not send anything else through the same path to compare..
Another challenge would be the synchronization of the two clocks at such
distance.

Perhaps they are simply using a distance which is not that precise.


Isaac

2011\09\23@110800 by Herbert Graf

picon face
On Fri, 2011-09-23 at 10:29 +1200, IVP wrote:
> > www.bbc.co.uk/news/science-environment-15017484
>
> I think the neutrinos just get excited by a trip to Italy
>
> The figure I've seen is 20ppm faster than light. They allegedly
> arrived 60ns before light would have, with an accountable
> error of 10ns
>
> One scientist asked why neutrinos haven't been observed (for
> whatever reason) ahead of supernovae, which they should do
> by a significant time period if at least one flavour of neutrino is
> 20ppm faster than light

The explanation I've seen is the effect is more pronounced the higher
the energy of the neutrinos. Neutrinos from supernovas are "relatively"
low energy.

This behaviour WAS supposedly observed at another experiment a short
time ago, but the result was within the margin of error so they
discounted it. In that case the neutrinos were of higher energy then
supernova, but not as high as this latest experiment.

This could potentially be VERY interesting news if the evidence holds,
we'll see!

TTYL

2011\09\23@110908 by Kerry Wentworth

flavicon
face
Isaac Marino Bavaresco wrote:
{Quote hidden}

The speed of light through a medium is (speed of light in a vacuum)/(index of refraction of medium)
The index of refraction is dependent on the wavelength of the light.
Neutrinos are not light.
So:
Is the index of refraction known for the entire path?
Is the index of refraction for light the same as for neutrinos?
Is the wavelength of neutrinos known to sufficient accuracy?

See http://en.wikipedia.org/wiki/Refractive_index

Inquiring minds want to know.

Kerry

2011\09\23@113627 by Isaac Marino Bavaresco

flavicon
face
Em 23/9/2011 12:07, Kerry Wentworth escreveu:
{Quote hidden}

Perhaps, but we are talking about sub-microsecond times (less than 1/16us).

This one seem too obvious, but only perhaps: Did they remember to take
in account the curvature of the surface of the earth? The GPS
measurements are surely on the surface of the earth. They would need to
extrapolate to the underground site the equipments are located. At a
distance of 732km the radii of the earth cannot be considered parallel.
The deeper you go, the closer two points on those radii are.


{Quote hidden}

These points are important also.


Isaac

2011\09\23@114737 by Yigit Turgut

picon face
Refraction index depends on lots of parameters not just the wavelength
of the source. It is a macroscopic manifestation of the molecular
structure. It's a scale to compare materials ratios of interactions
with vacuum where there is no interaction and light is at it's maximum
speed. Since they artificially generate neutrinos they have the very
specs of them. Also since they constructed the tunnel specifically for
this purpose, it is easy to calculate and measure the refractive index
through the propagation medium (the tunnel), fairly easy process.

Something completely different ; neutrino oscillations only show
duality at quantized levels thus none of these are necessary for
measuring the speed of sub-atomic particles.


On Fri, Sep 23, 2011 at 6:07 PM, Kerry Wentworth
<KILLspamkwentworthKILLspamspamskunkworksnh.com> wrote:
{Quote hidden}

>

2011\09\23@125010 by Jim Higgins

flavicon
face
Received from Isaac Marino Bavaresco at 09/23/11 14:23 UTC:

{Quote hidden}

Until now, the Large Hadron Collider has been demolishing theories rather than spawning new ones.  That leaves me more inclined to use the results just obtained to recalculate the speed of light thru rock (etc) along the path from Switzerland to Italy than to challenge Einstein.

Supposing the speed measurements are confirmed beyond doubt, next must come a coherent theory explaining it, otherwise all we have is an unexplained anomaly.  I imagine the theorists are off and running already.

2011\09\23@133059 by Gary Crowell

picon face
On Fri, Sep 23, 2011 at 9:47 AM, Yigit Turgut <RemoveMEy.turgutTakeThisOuTspamgmail.com> wrote:

>
> speed. Since they artificially generate neutrinos they have the very
> specs of them. Also since they constructed the tunnel specifically for
> this purpose, it is easy to calculate and measure the refractive index
> through the propagation medium (the tunnel), fairly easy process.
>
>
That's the problem... they were using artificial neutrinos.  Natural
neutrinos would be completely different.



----------------------------------------------
Gary A. Crowell Sr., P.E., CID+
Linkedin <http://www.linkedin.com/in/garyacrowellsr>
Elance<www.linkedin.com/redirect?url=http%3A%2F%2Fgaryacrowellsr%2Eelance%2Ecom&urlhash=kJm9>
 KE7FIZ <http://www.arrl.org

2011\09\23@141341 by Jim Higgins

flavicon
face
Received from Yigit Turgut at 09/23/11 15:47 UTC:

>Refraction index depends on lots of parameters not just the wavelength of
>the source. It is a macroscopic manifestation of the molecular structure.
>It's a scale to compare materials ratios of interactions with vacuum where
>there is no interaction and light is at it's maximum speed. Since they
>artificially generate neutrinos they have the very specs of them. Also since
>they constructed the tunnel specifically for this purpose, it is easy to
>calculate and measure the refractive index through the propagation medium
>(the tunnel), fairly easy process.


Not quite so easy because there isn't a 732 km tunnel.  Other than a bit of tunnel housing the equipment on each end, the path is thru the earth.  I'm sure the characteristics of that path can be estimated fairly closely, but how do they know for sure?  What are the margins of error on that estimate?  Would we still have faster than light neutrinos if we assume one or the other bookend values for the speed of light along that path.

Light is fastest in a vacuum.  It's slower in all other media.  If the speed of light calculated for the rocky path is too low, then neutrinos travelling at the true speed of light in that medium will appear to be travelling faster than light should travel in that medium.

2011\09\23@145548 by Isaac Marino Bavaresco

flavicon
face
Em 23/9/2011 15:00, Jim Higgins escreveu:
{Quote hidden}

How would they know the speed of light through rock?
It appears that they think the neutrinos are traveling though rock
faster than the light does in vacuum.

The neutrinos (almost) don't interact with matter. Perhaps their speed
in any media is the same.

Isaac

2011\09\23@145624 by William Couture

face picon face
On Fri, Sep 23, 2011 at 2:00 PM, Jim Higgins <spamBeGoneHigginsJspamBeGonespamsc.rr.com> wrote:
{Quote hidden}

Something exceeding the speed of light in the local medium is a well
known phenomena -- see Cherenkov radiation (i.e.
http://en.wikipedia.org/wiki/Cherenkov_radiation).

This is faster than the speed of light in a vacuum.

Bill

-- Psst...  Hey, you... Buddy...  Want a kitten?  straycatblues.petfinder.org

2011\09\23@151124 by Yigit Turgut

picon face
On Fri, Sep 23, 2011 at 9:00 PM, Jim Higgins <TakeThisOuTHigginsJEraseMEspamspam_OUTsc.rr.com> wrote:
> Received from Yigit Turgut at 09/23/11 15:47 UTC:
>
>>Refraction index depends on lots of parameters not just the wavelength of
>>the source. It is a macroscopic manifestation of the molecular structure.
>>It's a scale to compare materials ratios of interactions with vacuum where
>>there is no interaction and light is at it's maximum speed. Since they
>>artificially generate neutrinos they have the very specs of them. Also since
>>they constructed the tunnel specifically for this purpose, it is easy to
>>calculate and measure the refractive index through the propagation medium
>>(the tunnel), fairly easy process.
>
>
> Not quite so easy because there isn't a 732 km tunnel.  Other than a bit of
> tunnel housing the equipment on each end, the path is thru the earth.  I'm
> sure the characteristics of that path can be estimated fairly closely, but
> how do they know for sure?  What are the margins of error on that
> estimate?  Would we still have faster than light neutrinos if we assume one
> or the other bookend values for the speed of light along that path.

Whole propagation path is not vacuum surely, but the path geometry and
total distance is estimated safely. Maybe not precise down to cm scale
but I believe it's an acceptable approximation.  Can't say numbers
safely about the error margins but the measurement points to a speed
approximately 400 times more than the speed of light. It would be
still much more faster than "c" even if the propagation path
measurement has precision at km scale. The actual tolerance mentioned
on the original paper is originating from the heterogeneous and
anisotropic structure of the path after the vacuum tunnel. Exact
permittivity and conductivity tensors of the mediums between first
muon detector and Gran Sasso should be known for very high accuracy
calculations - which is not possible with today's tech. If between
medium was isotropic and homogeneous, propagation path could be
determined at nanoscale precision. Which I am sure that they would
construct the whole path as the tunnel if it was a requirement for
gathering the same results. Obviously, not necessary.

2011\09\23@190502 by IVP

face picon face
> The neutrinos (almost) don't interact with matter. Perhaps their
> speed in any media is the same

Don't forget that a vacuum isn't empty. It's full of particles that may
or may not and do and do not exist. Light photons might be disturbed
and slowed by gravitons, Higgs bosons, 4th dimension voids, and
who-knows-what-else, things that do not trouble neutrino

2011\09\23@200746 by Michael Watterson

face picon face
Jim Higgins wrote:
>
> Supposing the speed measurements are confirmed beyond doubt, next must come a
> coherent theory explaining it, otherwise all we have is an unexplained
> anomaly.  I imagine the theorists are off and running already.
>
>
>
>   If the Neutrinos have negative rest mass, which is feasible since they are never at rest, then they can go faster than speed of light.

The fine print of current theory isn't actually that nothing can go faster than the speed of light, but that the max speed of something with no mass is  speed of light in a vacuum and anything with mass becomes infinitely heavy  as  it tends to speed of light, thus no particle with mass can be accelerated to speed of light, only very close.

Perhaps Neutrinos can have a wavelength equal to size of Universe with maximal energy. With Minimal energy it then slows to speed of light ... An in between energy neutrino thus will be some speed between speed of light and everywhere at ones (infinite energy Neutrino).

Could then Neutrinos  of some  kind  account for  discrepancies  in observation of  Universe as it looks increasingly likely that the current ideas of Dark matter and Dark energy are hogwash.

Really I know nothing about this except that the "Speed of Light" law applies to Light and regular particles. Neutrinos even if they don't have negative mass are sufficiently odd that it's likely nothing other than our understanding of Neutrinos will change if they are going "faster than light in a Vacuum" Through loads of  rock too.

If they found atoms, light, electrons or protons etc going faster than  speed of light  you'd need to worrry. But they haven't

Instant Faster than Light "Transmission" with Quantum Entanglement.
It's not transmission faster than light sadly. You can't make an Ansible out of  it.
Imagine you have two randomly shuffled packs of cards. One here and an identical one at Alpha Centauri.
You do not examine them.
Quantum entanglement means you change the random cards here and the ones at Alpha Centauri change too.  But you can't even detect the change at Alpha Centauri as you don't know what the card layout was, so you don't know it changed.
However if both parties examine the cards and communicate they will find they have the same layout. So you can prove the entanglement took place, by ordinary information transfer at speed of light. But you can never use the quantum entanglement itself to signal with.

Pity. Because a pair  of these would be  handy http://en.wikipedia.org/wiki/Ansible
Of course like "Stargates" (an Idea that seriously pre-dates Stargate) the problem is you have only slower than light craft for distribution or speed of light to  distribute plans.


2011\09\23@201345 by Michael Watterson

face picon face
William Couture wrote:
>
> Something exceeding the speed of light in the local medium is a well
> known phenomena -- see Cherenkov radiation (i.e.
> http://en.wikipedia.org/wiki/Cherenkov_radiation).
>
> This is faster than the speed of light in a vacuum.
>
> Bill
>
>  
No I don't think so.
You can get movement in a Medium faster than light in the Medium. But it's slower than light in a vacuum

For example you can make glass that slows light but allow other things through faster (but still slower than Light in a vacuum)

2011\09\23@202444 by Michael Watterson

face picon face
Michael Watterson wrote:
>
> Pity. Because a pair  of these would be  handy
> http://en.wikipedia.org/wiki/Ansible
> Of course like "Stargates" (an Idea that seriously pre-dates Stargate)
> the problem is you have only slower than light craft for distribution or
> speed of light to  distribute plans.
>
>  
>
>
>
>   A more detailed explanation of why an Ansible doesn't work
io9.com/5584356/can-i-build-an-ansible-to-communicate-across-the-cosmos

2011\09\23@222645 by Isaac Marino Bavaresco

flavicon
face
Em 23/9/2011 21:07, Michael Watterson escreveu:

> Perhaps Neutrinos can have a wavelength equal to size of Universe with
> maximal energy. With Minimal energy it then slows to speed of light ...
> An in between energy neutrino thus will be some speed between speed of
> light and everywhere at ones (infinite energy Neutrino).

Aren't those called tachyons?

2011\09\24@003233 by Jim Higgins

flavicon
face
Received from Michael Watterson at 09/24/11 00:07 UTC:

>Jim Higgins wrote:
>>
>>Supposing the speed measurements are confirmed beyond doubt, next must come
>>a coherent theory explaining it, otherwise all we have is an unexplained
>>anomaly.  I imagine the theorists are off and running already.
>
>
>If the Neutrinos have negative rest mass, which is feasible since they are
>never at rest, then they can go faster than speed of light.


I'm not a physicist, just a curious layman who avidly read Scientific American way back when it published more articles on particle physics than on sociological topics after scrubbing them politically correct.

As I understand it (which isn't saying a whole lot)...  the neutrino's observed interactions are all via the gravitational and weak forces and the gravitational interactions are "positive" (meaning they attract other positive masses) suggesting positive (though incredibly small) mass for the neutrino.  A massless neutrino could travel *AT* the speed of light... actually *must* travel at the speed of light.  But one with positive mass cannot.

I don't begin to be able to do all the necessary math, but the math I can do doesn't seem to allow a theoretical neutrino with negative mass to travel FTL.  It seems that requires one with imaginary mass - mass that if squared would be negative.  Then FTL speeds seem possible, but that neutrino would be a new neutrino not previously discovered and not predicted by the Standard Model... which isn't to say it can't be, just that we haven't seen it.  Perhaps we don't see it because we don't look for it because we don't predict it.  I have no clue how to observe a particle with imaginary mass.


>The fine print of current theory isn't actually that nothing can go faster
>than the speed of light, but that the max speed of something with no mass is
>speed of light in a vacuum and anything with mass becomes infinitely heavy
>as it tends to speed of light, thus no particle with mass can be accelerated
>to speed of light, only very close.


I'd be inclined to think that the *only* speed at which a truly massless particle can travel is the speed of light.  But with any mass at all, however infinitesimal, speed would be limited by the speed of light.  (Based on current knowledge and fully peer reviewed observation.)


>Perhaps Neutrinos can have a wavelength equal to size of Universe with
>maximal energy.  With Minimal energy it then slows to speed of light... An
>in between energy neutrino thus will be some speed between speed of light
>and everywhere at ones (infinite energy Neutrino).


Or could neutrinos simply be nodal wave points (a better descriptive term eludes me) made up of the sum of several/many waves each with different frequencies.  If so the nodal point (the neutrino) could be observed to move faster than light even though none of the individual waves comprising it do so individually.


>Could then Neutrinos of some kind account for discrepancies in observation
>of  Universe as it looks increasingly likely that the current ideas of Dark
>matter and Dark energy are hogwash.


I haven't heard anything yet that makes either or both of the "dark" explanations hogwash, though "dark matter" does seem to stand apart from any other theory of physics.  Last I heard the proponents were hanging their hats on the mass of the neutrino, which is "known," but with an uncertainty that straddles the fence.  A hair heavier and we have an oscillating (expanding now, but eventually collapsing) universe, a hair lighter and we have a constantly expanding one.  It will take a more precise determination of the mass of the neutrino to determine the fate of the "dark" theories.  And that's about all "dark" has to do with neutrinos as far as I know.  It's unrelated to their ability (or not) to travel FTL.


>Really I know nothing about this except that the "Speed of Light" law
>applies to Light and regular particles.  Neutrinos even if they don't have
>negative mass are sufficiently odd that it's likely nothing other than our
>understanding of Neutrinos will change if they are going "faster than light
>in a Vacuum" Through loads of rock too.


Well, observations all seem to confirm that neutrinos have incredibly small, but positive, mass.  Their interactions with other matter are at least partly gravitational.  I don't see how those two things can be and yet the neutrino still be so "alien" as to "violate" the universal speed limit.  I see terms like "regular particles" and "sufficiently odd" above, but those have no definitions in particle physics that I'm aware of.  But then there's a *lot* in particle physics I'm not aware of.

I'm guessing this whole FTL thing will be explained in time and when it is I don't expect to see the universal speed limit broken.  Why not?  I guess because it would break too much else that fits together too nicely.  "Nicely" not being a term well defined in particle physics.  ;-)

What I'm most interested in is the Higgs boson, something the LHC is intended to find.  Finding it supports the Standard Model while conclusively demonstrating it doesn't exist supports one of the Higgsless models.  I'd prefer to find it because conclusively proving it doesn't exist is a messy proposition.  You essentially have to select something in a Higgsless model that isn't in the Standard Model *and* that conclusively rules out the existence of the Higgs and then you need to experimentally observe that thing.  I'm not so sure (meaning I really don't know) whether the Higgsless models lend themselves to physical observation as well as the Standard Model has, so that could be problematic also.  All in all I'd really like to find the Higgs.

2011\09\24@005424 by RussellMc

face picon face
This thread seems to have got to the point where it is (again) worth
noting that life is complex - it has real and imaginary parts.
(The groans can be heard even from here).

Slightly closer to real world is the photon's unreal world.
>From a photon's point of view: All photons must [tm]  travel
instantaneously anywhere, but cannot travel at all, and indeed never
need to as any given photon is instantaneously everywhere, as they all
are.  No photon gets to anywhere before or after any other one.
Indeed, there is no before or after. No here or there. No then and
now.

Just because we see things differently than they do, who's to say they
are wrong? :-)


       Russel

2011\09\24@025717 by IVP

face picon face
> "dark matter" does seem to stand apart from any other theory of physics

I don't know if dark matter is anything special, just they hadn't
found unaccounted-for mass yet, whether it be hard-to-detect
wandering planets or other non-radiating debris. Even objects in
the theorised Oort Cloud

http://en.wikipedia.org/wiki/Oort_cloud

which forms the outer limit of the Solar System, can't be seen directly

http://www.newscientist.com/article/dn13362-giant-ropes-of-dark-matter-found-in-new-sky-survey.html

New method 'confirms dark energy'

http://www.bbc.co.uk/news/science-environment-13462926

2011\09\24@040514 by RussellMc

face picon face
> New method 'confirms dark energy'

Yes, but that's only until next week.


2011\09\24@041258 by IVP

face picon face
>> New method 'confirms dark energy'
>
> Yes, but that's only until next week.

The neutrinos will have a laugh just before us the

2011\09\24@053947 by RussellMc

face picon face
40,000 bugs found in CERN software so far. So far.

<http://www.marketwatch.com/story/cern-chooses-coverity-to-ensure-accuracy-of-large-hadron-collider-software-2011-09-22>

Not much hope for their FTL aspirations then?


2011\09\24@073515 by cdb

flavicon
face
::No photon gets to anywhere before or after any other one.
::Indeed, there is no before or after. No here or there. No then and
::now.

That means they must all congregate at the one or both Poles at the same time and all we see are their reflections.

Colin
--
cdb, RemoveMEcolinspamTakeThisOuTbtech-online.co.uk on 24/09/2011
Web presence: http://www.btech-online.co.uk   Hosted by:  http://www.justhost.com.au
 This email is to be considered private if addressed to a named  individual or Personnel Department, and public if addressed to a blog,  forum or news article.

2011\09\24@085850 by Carey Fisher

face picon face
On Sat, Sep 24, 2011 at 5:39 AM, RussellMc <apptechnzEraseMEspam.....gmail.com> wrote:

> 40,000 bugs found in CERN software so far. So far.
>
> ....................................
.......................................

>                 R
> --
>
> <http://www.piclist.com>
>
It's a press release from the software analysis company.  Wonder how they
counted the bugs and how many actually could affect the "research accuracy"..
Care

2011\09\24@092344 by RussellMc

face picon face
> It's a press release from the software analysis company.  Wonder how they
> counted the bugs and how many actually could affect the "research accuracy".

Yes.
It seemed a shame to spoil a good story :-)
But, it does make the point that software is usually less than
methodical and consistent and that maximising these atytributes may
[tm] be a good idea where rigor is required.

I initially misread their heading and though that they were sending
their software to Coventry :-).



        R

2011\09\24@100906 by RussellMc

face picon face
> ::No photon gets to anywhere before or after any other one.
> ::Indeed, there is no before or after. No here or there. No then and
> ::now.
>
> That means they must all congregate at the one or both Poles at the same
> time and all we see are their reflections.

At least :-).
At Light Speed (LS)
- Time stops
- Distance drops to zero.
- Velocity, distance, time, ... are meaningless concepts.
Only photons can travel AT LS and photons MUST travel at LS.
If Neutrinos have zero rest mass they too travel AT light speed and
are also "timeless".
I Ns have some mass they travel < LS.
If N's have negative mass they travel FTL

Einstein's theory does not say that nothing can exceed light speed.
It just says that nothing with non zero rest mass can travel AT LS.

Tunneling gets you there.
Quite HOW to tunnel is the question

2011\09\24@132807 by Michael Watterson

face picon face
On 24/09/2011 15:08, RussellMc wrote:
> I Ns have some mass they travel<  LS.
> If N's have negative mass they travel FTL
>
Another suggestion is that Neutrino mass is positive, but on the Imaginary Axis. i.e  Square root -1

However
an Almost zero negative mass Neutrino would seem to go at speed of light, unless you measured very carefully. A higher energy might imply a more negative mass thus more noticeably faster than speed of light.

I saw someplace some ask if Neutrinos might be the hypothetical Tachyons.

2011\09\24@163949 by RussellMc

face picon face
> .. an Almost zero negative mass Neutrino would seem to go at speed of
light, unless you measured very carefully. A higher energy might imply a
more negative mass thus more noticeably faster than speed of light.

I saw someplace some ask if Neutrinos might be the hypothetical Tachyons.
>>/


My recollection from figuring done 10 to 20 years ago is that past C,
energy initially DROPS as velocity increases, reaches a minimum about
2.X c and then climbs again. That depends on how you interpret the
imaginary quantities and I may well have got it wrong.
I wrote a short never published (no surprise ;-) )   "Probability 0"
type Science Fact story based on this re a tunnelling FTL drive.
If there ever is a FTL drive it MUST tunnel

      R

2011\09\25@113608 by Electron

flavicon
face

By the way, could anybody explain this (IMHO) Relativity paradox?

first of all:
"Ether doesn't exist" = TRUE, relativity says. OK.

now, I am in a spaceship, I orbit around the Earth at very high
speed for a certain time, when I'm back home all other people
(which resided on the Earth) look older than I am. Thus time in
my spaceship was slowed, or on the Earth it was quickened.
But relativity says that it could have been the Earth to orbit
very quickly around my spaceship, or my spaceship around it..
as all is relative and NO ETHER (fixed space coordinates) EXISTS!

To me this sounds very contraddictory!

Is there any convincing explanation for that, that doesn't break
neither relativity theory nor asks me to have faith in something?

Cheers,
Mario

2011\09\25@114536 by Electron

flavicon
face

PS: sorry with Ether I mean Aether.. my ItalianEnglish has striken back :D


{Quote hidden}

>Mario

2011\09\25@124504 by Chris Roper

picon face
There is no paradox and no faith required. What it is saying is that
there is no fixed point of reference, so mathematically you would get
the same result, regardless of who was stationary and who was moving
"Relative" to the other.

On 25 September 2011 17:45, Electron <EraseMEelectron2k4spaminfinito.it> wrote:
{Quote hidden}

>

2011\09\25@124820 by Chris Roper

picon face
oops:
Just reread your question and I agree there is a paradox.
Which body gets older, the one orbiting ore that one orbited.

On 25 September 2011 17:45, Electron <RemoveMEelectron2k4EraseMEspamEraseMEinfinito.it> wrote:
{Quote hidden}

>

2011\09\25@132905 by Wouter van Ooijen

face picon face
> now, I am in a spaceship, I orbit around the Earth at very high
> speed for a certain time, when I'm back home all other people
> (which resided on the Earth) look older than I am. Thus time in
> my spaceship was slowed, or on the Earth it was quickened.
> But relativity says that it could have been the Earth to orbit
> very quickly around my spaceship, or my spaceship around it..
> as all is relative and NO ETHER (fixed space coordinates) EXISTS!

You can't do this without (very large) acceleration and deceleration. You can't accelerate the earth and have the same effect, you will notice when *you* accelerate. Hence the two experiments (you accelerate and orbit the earth, or the earth accelerates and orbits you) are not symmetric at all.

--
Wouter van Ooijen

-- -------------------------------------------
Van Ooijen Technische Informatica: http://www.voti.nl
consultancy, development, PICmicro products
docent Hogeschool van Utrecht: http://www.voti.nl/hvu

2011\09\25@135711 by RussellMc

face picon face
> But relativity says that it could have been the Earth to orbit
> very quickly around my spaceship, or my spaceship around it..
> as all is relative and NO ETHER (fixed space coordinates) EXISTS!
>
> To me this sounds very contradictory!

1. Some guy you know more or less cleared that up in something he
wrote about 96 years ago.

2. But a key relevant difference is that you were subject to
acceleration forces to achieve the velocity difference and the world
wasn't.

3. Also, fwiw, you will need to travel in a non orbital path to
achieve useful relativistic speeds,

4. and if you did find an object that you  could orbit at usefully
relativistic speeds you would be being subject to continual
acceleration which may be relevant to outcomes.

>  nor asks me to have faith in something?

5. **Everything** requires faith in something.


         Russel

2011\09\25@165359 by Kerry Wentworth

flavicon
face
RussellMc wrote:
{Quote hidden}

So, I take off in a space ship and make 1 circumnavigation of the galaxy, accelerating at 1G for the first half of the trip and decelerating at 1G for the second half.  Meanwhile, my evil twin stays here in his 1G  field.  When I get back, who is old?

Kerry

2011\09\25@172417 by RussellMc

face picon face
> So, I take off in a space ship and make 1 circumnavigation of the
> galaxy, accelerating at 1G for the first half of the trip and
> decelerating at 1G for the second half.  Meanwhile, my evil twin stays
> here in his 1G  field.  When I get back, who is old?

Unless we have input from a person skilled in the art of relatavistic
playing we rapidly get into rubbish answers here. I've done enough
dabbling to know that I can produce figures that are probably wrong,
but

- At a steady 1 G relative to the non-existent ether you reach C in 1
year, or slightly less [tm] if you don't have infinite propellant,
thereafter you travel at about C.

- Your evil twin is scattered molecules millenia ago. Deep-ending on
how close to C you managed, you are youngish.



   R

2011\09\25@202419 by IVP

face picon face
> But relativity says that it could have been the Earth to orbit
> very quickly around my spaceship, or my spaceship around it

> Is there any convincing explanation for that, that doesn't break
> neither relativity theory nor asks me to have faith in something?

As I see it -

If it were true then we, in fact everything, would be as ageless as
photons (in time as we know it so far)

The Earth around which you are orbiting is stationary with respect
to spacetim

2011\09\26@052749 by Electron

flavicon
face
At 02.23 2011.09.26, you wrote:
>> But relativity says that it could have been the Earth to orbit
>> very quickly around my spaceship, or my spaceship around it
>
>> Is there any convincing explanation for that, that doesn't break
>> neither relativity theory nor asks me to have faith in something?
>
>As I see it -
>
>If it were true then we, in fact everything, would be as ageless as
>photons (in time as we know it so far)
>
>The Earth around which you are orbiting is stationary with respect
>to spacetime

You mean there's a fixed reference for space and time?

2011\09\26@061527 by IVP

face picon face
>>The Earth around which you are orbiting is stationary with respect
>>to spacetime
>
> You mean there's a fixed reference for space and time?

You mean there isn't ? ;-)

Everything is/has its own reference

Take the well-known travelling clock example. A clock which is
moving passes time slower than one which is moving less fast.
Which is true because the clocks in GPS satellites need constant
correction. The satellites are moving relatively fast compared with
the reference of interest - us

Applying that to your paradox, an object orbiting The Earth will
age more slowly. If The Earth was orbiting the object then The
Earth would age more slowly

If they were orbiting each other equally (like binary stars or black
holes do) then they would not appear, to each other, to be ageing
unequally, if they were moving at the same speed. However, to a
slower-moving observer they would be ageing equally more slowly
than the observer

Any two objects connected orbitally perturb each other and change
the apparent passage of time. A satellite steals gravitational energy
from The Earth *, which in turn wobbles only ever so ever so slightly,
due to the enormous mass difference between a satellite and The
Earth. An elliptical orbit of a satellite will cause The Earth to alternately
accelerate and deccelerate minutely, causing temporal fluctuations

* energy stealing is the principal behind slingshotting spacecraft and
one method of detecting exoplanets and other companion objects

2011\09\26@101556 by Kerry Wentworth

flavicon
face
RussellMc wrote:
{Quote hidden}

When I compare my clock to his, is his running faster, slower, or at the same speed?
When he compares my clock to his, is mine running faster, slower, or at the same speed?

Kerry

2011\09\26@110425 by Carey Fisher

face picon face
On Sun, Sep 25, 2011 at 11:34 AM, Electron <RemoveMEelectron2k4spam_OUTspamKILLspaminfinito.it> wrote:

{Quote hidden}

This is also know as the Twins Paradox.  Wikipedia <
http://en.wikipedia.org/wiki/Twin_paradox> has a good explanation that
includes the interesting phrase "according to a naive application of time
dilation <http://en.wikipedia.org/wiki/Time_dilation>, each should
paradoxically <http://en.wikipedia.org/wiki/Paradox> find the other to have
aged more slowly." It then goes on to explain in pedantic detail, the
resolution of the paradox.

Carey Fishe

2011\09\26@125803 by Electron

flavicon
face

Bingo :D Thanks :o


At 17.03 2011.09.26, you wrote:
{Quote hidden}

>


'[OT] Speed-of-light experiments give baffling resu'
2011\10\08@031059 by IVP
face picon face
The barman says "Sorry, we don't serve neutrinos here"

A neutrino goes into a ba

2011\10\08@041429 by Electron

flavicon
face
At 09.10 2011.10.08, you wrote:
>The barman says "Sorry, we don't serve neutrinos here"
>
>A neutrino goes into a bar

Does it prove that barmens think faster than light? :D

2011\10\08@042729 by IVP

face picon face
>>The barman says "Sorry, we don't serve neutrinos here"
>>
>>A neutrino goes into a bar
>
> Does it prove that barmens think faster than light? :D

It does show what remarkable eyesight and attention to
detail they have

Can you get this one quicker than my sister-in-law -

Two goldfish are in a tank. One says to the other "So,
how long have you been in the army ?

2011\10\08@071130 by RussellMc

face picon face
> The barman says "Sorry, we don't serve neutrinos here"
> A neutrino goes into a bar


> Can you get this one quicker than my sister-in-law -
>
> Two goldfish are in a tank. One says to the other "So,
> how long have you been in the army ?"

_______________________

Try this

*** PLEASE DO NOT EXPLAIN IT ON LIST !!!! ***

Just say if you understand it.

NB - this is meant to be done orally & not written.
It has been adjusted slightly  to make it work semi-properly when
written - SO the written version is slightly wrong but if you read it
the iral version will be OK :-).
..
Read it to someone, or to yourself (or have someone read it to you :-) ).

Simple as this may or may not seem, especially in the context, it can
take some people from hours to never to understand it.

             Time flies
             You can't
             They fly too fast

________________________________

And:

There are 10 types of people.
Those who understand binary and those who don't.

_________________________________

I thought about telling the one about a neutrino going into a bar but
I'll leave it for Joe to tell.


           Russel

2011\10\08@073843 by IVP

face picon face
> I thought about telling the one about a neutrino going into a bar but
> I'll leave it for Joe to tell.

Tch, yes, yes, I'll got to i

2011\10\08@074829 by cdb

flavicon
face
::Two goldfish are in a tank. One says to the other "So,
::how long have you been in the army ?"

I can think of another one similar to that, sadly not fit for this august list, but fans of 'Not the Nine o' clock news' and a very early Blackadder (they reused the joke from a radio series of NTNOCN), may well ring a bell.

Colin
--
cdb, EraseMEcolinspamspamspamBeGonebtech-online.co.uk on 8/10/2011
Web presence: http://www.btech-online.co.uk   Hosted by:  http://www.justhost.com.au
 This email is to be considered private if addressed to a named  individual or Personnel Department, and public if addressed to a blog,  forum or news article.

2011\10\08@075355 by cdb

flavicon
face
::Time flies
::You can't
::They fly too fast

That ones got me at the moment, but...

Time flies like an arrow; fruit flies like a banana

Colin
--
cdb, RemoveMEcolinKILLspamspambtech-online.co.uk on 8/10/2011
Web presence: http://www.btech-online.co.uk   Hosted by:  http://www.justhost.com.au
 This email is to be considered private if addressed to a named  individual or Personnel Department, and public if addressed to a blog,  forum or news article.

2011\10\08@080323 by cdb

flavicon
face
OK, it suddenly made sense, just as I was about to give up!  Very good - Naughtyfeet reports that it was first printed in the 1930's issue of Boys' Life.

Colin
--
cdb, colinSTOPspamspamspam_OUTbtech-online.co.uk on 8/10/2011
Web presence: http://www.btech-online.co.uk   Hosted by:  http://www.justhost.com.au
 This email is to be considered private if addressed to a named  individual or Personnel Department, and public if addressed to a blog,  forum or news article.

2011\10\08@111058 by Chris Roper

picon face
As a joke I am sorry to say it Tanked :)

Bring on the 'Not the Nine o'clock News', I have it all on VHS but
hive no functional VHS players left :

2011\10\08@113552 by RussellMc

face picon face
> Bring on the 'Not the Nine o'clock News', I have it all on VHS but
> hive no functional VHS players left :)

Not yet, anyway.


2011\10\08@162436 by IVP

face picon face
> Time flies like an arrow; fruit flies like a banana

Tits like coconuts. So do squirrels and sparrows

2011\10\08@171254 by Chris Roper

picon face
what is the air seep velocity of a Sparrow?

On 8 October 2011 22:23, IVP <spamBeGonejoecolquittSTOPspamspamEraseMEclear.net.nz> wrote:
>> Time flies like an arrow; fruit flies like a banana
>
> Tits like coconuts. So do squirrels and sparrows
>
>

2011\10\08@171312 by Chris Roper

picon face
Air Speed that is :)


On 8 October 2011 23:12, Chris Roper <KILLspamcaroperspamBeGonespamgmail.com> wrote:
> what is the air seep velocity of a Sparrow?
>
> On 8 October 2011 22:23, IVP <EraseMEjoecolquittspamEraseMEclear.net.nz> wrote:
>>> Time flies like an arrow; fruit flies like a banana
>>
>> Tits like coconuts. So do squirrels and sparrows
>>
>> -

2011\10\09@085706 by Electron

flavicon
face
At 13.10 2011.10.08, you wrote:
>There are 10 types of people.
>Those who understand binary and those who don't.

This is extremely easy.. if you know binary. ;)

2011\10\09@093339 by RussellMc

face picon face
> >There are 10 types of people.
> >Those who understand binary and those who don't.

> This is extremely easy.. if you know binary. ;)

But, probably only 1 in 10 people do.


              Russel

2011\10\09@102350 by Wouter van Ooijen

face picon face
> But, probably only 1 in 10 people do.

Is that is base-googol?

--
Wouter van Ooijen

-- -------------------------------------------
Van Ooijen Technische Informatica: http://www.voti.nl
consultancy, development, PICmicro products
docent Hogeschool van Utrecht: http://www.voti.nl/hvu

2011\10\09@120551 by Chris Roper

picon face
I did expect one of you Monty Python fans to reply:

"With or without the  coconuts?"

:)

On 8 October 2011 23:12, Chris Roper <@spam@caroper@spam@spamspam_OUTgmail.com> wrote:
> what is the air seep velocity of a Sparrow?
>
> On 8 October 2011 22:23, IVP <spamBeGonejoecolquittspamKILLspamclear.net.nz> wrote:
>>> Time flies like an arrow; fruit flies like a banana
>>
>> Tits like coconuts. So do squirrels and sparrows
>>
>> -

2011\10\09@153231 by IVP

face picon face


>I did expect one of you Monty Python fans to reply:

Sorry, distracted, dodging a dead co

2011\10\09@181809 by Robin D. Bussell

flavicon
face


On 9 Oct 2011, at 14:35, "RussellMc" <.....apptechnzspam_OUTspamgmail.com> wrot

>>> There are 10 types of people.n
>>> Those who understand binary and those who don't.
>
>> This is extremely easy.. if you know binary. ;)
>
> But, probably only 1 in 10 people do

It's annoying that that exchange only works in print as it's very elegant :)

Along similar lines:
http://xkcd.com/953/

Though rewriting it as "a scale of 1 to 100" might add another layer of intrigue :)
Cheers,
       Robin.

2011\10\09@190232 by Chris Roper

picon face
Computers also  solved Shakespeare's equation:
2B OR NOT 2B = -1

On 10 October 2011 00:17, Robin D. Bussell <TakeThisOuTRobinB.....spamTakeThisOuTexcelerate.info> wrote:
{Quote hidden}

>

2011\10\10@033445 by alan.b.pearce

face picon face
>
> And:
>
> There are 10 types of people.
> Those who understand binary and those who don't.
>
And today is binary day ... 10/10/11 ...


-- Scanned by iCritical.

2011\10\10@053100 by RussellMc

face picon face
> Computers also  solved Shakespeare's equation:
> 2B OR NOT 2B = -1

Very good!
I explained that to my wife.
She was suitably non-plussed.

But. it must be moving at the speed of light, as the answer is always
-1 for all numbers in all bases EXCEPT in unary.

Unary is the number system that photons count in.


      Russell.

2011\10\13@131912 by Dave Lagzdin

picon face
> On 8 October 2011 17:13, Chris Roper <.....caroperspamRemoveMEgmail.com> wrote:
> Air Speed that is :)

"I'm so sorry, He's from Barcelona"
err-... nevermind...

2011\10\13@133144 by John Gardner

picon face
....2B OR NOT 2B = -1

!  That's pretty funny  :)

Some days it IS worth chewing through the restraints...

Jac

2011\10\13@161735 by IVP

face picon face
> Some days it IS worth chewing through the restraints...

They let you keep your teeth the

2011\10\13@183026 by RussellMc

face picon face
You'd be surprised what you can achieve if you sharpen your gums long enough.


                  R

On 14 October 2011 09:17, IVP <RemoveMEjoecolquittspamspamBeGoneclear.net.nz> wrote:
>> Some days it IS worth chewing through the restraints...
>
> They let you keep your teeth the

2011\10\13@185641 by John Gardner

picon face
Very droll, ahh... Gentlemen - I use the term loosely.

:

2011\10\13@193212 by RussellMc

face picon face
> Very droll, ahh... Gentlemen - I use the term loosely.

The term cannot be used loosely if used properly.
As CS Lewis notes, or noted, a Gentleman is a male person who owns land.
As I do (in the manner that the term "own" is usually used in that
context" "I are one".

I'm not at all sure that Joe is though :-).


            Russel

2011\10\13@202012 by IVP

face picon face
>> Very droll, ahh... Gentlemen - I use the term loosely.
>
> As CS Lewis notes, or noted, a Gentleman is a male
> person who owns land

I do have a couple of acres. It's this chair I thin

2011\10\15@170042 by Josh Koffman

face picon face
Possible solution to the problem!

http://www.dvice.com/archives/2011/10/speedy-neutrino.php

Josh
-- A common mistake that people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools.
        -Douglas Adams

2011\10\15@174556 by IVP

face picon face
> Possible solution to the problem!
>
> http://www.dvice.com/archives/2011/10/speedy-neutrino.php

Aren't GPS clocks compensated for relativity anyway ? Seems
unlikely that all those boffins at CERN haven't considered that
when looking for the 60ns discrepancy

IMVHO

450 miles time-of-flight at light speed is 2.41ms

Off by 60ns = error of 0.0025% = 59ft per 450 miles

Either neutrinos > c or GPS doesn't work as advertised

????

Jo

2011\10\15@175321 by John Gardner

picon face
....Aren't GPS clocks compensated for relativity anyway ?

Yes, though there's a story that the original GPS implementation
included the option to turn off the compensation - In case Einstein
was wrong, apparently. Ya gotta love engineers...  :)

Jac

2011\10\15@181616 by Chris Roper

picon face
I hope they also included parachutes in case Newton was wrong :)

On 15 October 2011 23:53, John Gardner <spamBeGonegoflo3@spam@spamspam_OUTgmail.com> wrote:
> ...Aren't GPS clocks compensated for relativity anyway ?
>
> Yes, though there's a story that the original GPS implementation
> included the option to turn off the compensation - In case Einstein
> was wrong, apparently. Ya gotta love engineers...  :)
>
>  Jack
>

2011\10\15@225132 by Jim Higgins

flavicon
face
Received from IVP at 10/15/11 21:45 UTC:

> > Possible solution to the problem!
> >
> > http://www.dvice.com/archives/2011/10/speedy-neutrino.php
>
>Aren't GPS clocks compensated for relativity anyway ? Seems
>unlikely that all those boffins at CERN haven't considered that
>when looking for the 60ns discrepancy
>
>IMVHO
>
>450 miles time-of-flight at light speed is 2.41ms
>
>Off by 60ns = error of 0.0025% = 59ft per 450 miles
>
>Either neutrinos > c or GPS doesn't work as advertised


Not at all.  What the article is trying to describe is somewhat akin to the following non-Einsteinian analogy.

A train is traveling at 5 feet per second.  At the rear of a flatcar is a rabbit.  The flatcar is 50 feet long.  The maximum speed at which this rabbit can run is 25 fps - this is an absolute physical constant - and he can attain this speed instantaneously.  Alongside the tracks is an observer.  The rabbit begins running and the observer starts his timer.  When the rabbit has moved 50 feet with respect to the observer the observer stops his timer.  The timer shows 1.82 seconds.  So the rabbit traveled at 50 feet / 1.82 seconds or 27..5 fps.  Neutrino rabbit broken the rabbit speed barrier and has proven Einstein wrong!  Or has he?

It's not the best analogy, but it does indicate that frame of reference is important.  Wrap your head around the analogy and then read the article again.


2011\10\15@233325 by IVP

face picon face

> It's not the best analogy, but it does indicate that frame of reference is
> important

Hi Jim,

my thinking was that relativity effects on GPS satellites and their slower
timekeeping is well understood and is compensated for, as your bunny
watcher would need to do

http://en.wikipedia.org/wiki/Global_Positioning_System

Refering to the section 'Precise Monitoring'

I don't know what system CERN uses, but you might think it 'obvious'
that they'd first suspect GPS errors. They must surely have access to
terrestrial clocks to determine propagation and latency times of their
equipment, and especially before announcing a faster-than-light event

Joe

2011\10\16@123834 by Electron

flavicon
face
At 00.16 2011.10.16, you wrote:
>On 15 October 2011 23:53, John Gardner <TakeThisOuTgoflo3spamspamgmail.com> wrote:
>> ...Aren't GPS clocks compensated for relativity anyway ?
>>
>> Yes, though there's a story that the original GPS implementation
>> included the option to turn off the compensation - In case Einstein
>> was wrong, apparently. Ya gotta love engineers...  :)
>
>I hope they also included parachutes in case Newton was wrong :)

ROTFLOL =)

2011\10\16@131437 by Jim Higgins KB3PU

flavicon
face
Received from IVP at 10/16/11 03:32 UTC:

{Quote hidden}

Hi Joe,

Yes, it seems fairly obvious once explained after the fact.  One would think the folks at CERN would have taken that into account.  But thinking of it and then implementing it properly in software might be two different things.  I think we had a NASA probe go astray years back over the use of US Customary vs CGS units in a single calculation.  And then there was the hardware problem with the Hubble mirror.  Explanations for both fairly easily comprehended by laymen after the fact, but missed - or mis-implemented - at the time by the experts.  So complete omission or incomplete implementation, I don't know.

Anyhow, the article accounted for the deviation from Einstein's theory, but I don't recall it saying explicitly that they had actually found that this had been demonstrated to be *THE* actual source of error.  The article says, "...but they MAY [emphasis mine] have forgotten one critical thing: relativity."  I'd guess they did verify it wasn't accounted for, but are being careful pending peer review.

Bottom line?  You won't go broke betting on Einstein.  ;-)

2011\10\16@132230 by RussellMc

face picon face
Caution: Train of consciousness post "develops".
Some brain may explode.
You have been warned!
Just walk away slowly now with your brain in sight and no sudden moves..
___________


> >> ...Aren't GPS clocks compensated for relativity anyway ?
> >>
> >> Yes, though there's a story that the original GPS implementation
> >> included the option to turn off the compensation - In case Einstein
> >> was wrong, apparently. Ya gotta love engineers...  :)
> >
> >I hope they also included parachutes in case Newton was wrong :)
>
> ROTFLOL =)

That's all very well, but what if Bernoulli was wrong, or Nusselt?, or Prandtl.
OR NEWTON !!!? (Where would you get your apples from then tell me.)

Speaking of famous foundation builders.

I stood where Gallileo stood.
I didn't do what Gallileo did*.
'They' may have been upset.
Besides which, I didn't have any Cannon balls.
And, if I did, the stair is long and very vey very winding.
An the Italian department of homeland security may have noticed them
on their XRay machines and decided tat I was not a patriot [tm].

* There is doubt whether G' really did the experiment. But I have
little doubt that he stood at the outer/lower lip and pondered.

_____

What if Darwin was wrong?
What if there IS creation?
What if .... ?

No. Not today :-).

I never got to knowingly stand anywhere that Darwin stood.
I did once quite unawares until I arrived, make it to with a foot of
The Red Baron's compass and joystick.
Tough lot these Aussies!
But, not as tough as the All Blacks! :-).
Game on! (next weekend).
"Rive la France!!!"

I'd like to visit Temple Mount in Jerusalem. At the North West corner
there isn't a staircase. It doesn't lead to the Roman Tower Fort that
isn't in that corner anymore. But 2000 years ago there was and there
was and it wa named "Antonia" after Mark Anthony, who was Herod the
(very) great's patron and who committed suicide with Cleopatra. Just
because it's in Shakespeare it doesn't mean it isn't true.
They carried 'St Paul' [tm] up the stairs into Antonia to get him away
from the crowd. He asked them to put him down a mo while he talked to
the crowd. They did and he did. He stood on the stairs. The crowd got
very annoyed, again. I'd like to stand in the Nth-West corner of the
temple and see how much St Paul feeling you get after 2000 years.

An on the "stage" in the auditorium at Ephesus, if they let me.

I have crossed trails wit the more recent Mark Paul in far north west
China (no Roman tower). It took me a while to work out who this Mark
Paul fellow who they were talking about was.



          Russell




           R

2011\10\16@132545 by RussellMc

face picon face
                     ... after the event?

> Bottom line?  You won't go broke betting on Einstein.  ;-)

Before or ...














__________________

Being "funny" was more important than it withstanding scrutiny.

2011\10\16@173711 by Dave Tweed

face
flavicon
face
Jim Higgins wrote:
{Quote hidden}

That's a terrible analogy, and also, the explanation offered on the website
is worthless as well. It is either oversimplified or simply wrong; in either
case, it doesn't aid in understanding either the problem or the proposed
solution.

First of all, LNGS in Gran Sasso, Italy is southeast of CERN in Geneva,
Switzerland and the earth rotates west-to-east, so the detector is moving
*away* from the beam of neutrinos, not toward as the article states. In any
case, the movement is on the order of 2 feet during the flight time of the
pulse, which is about 2 orders of magnitude too low to account for the
observed offest in timing.

It really isn't clear from the wording they used, but it seems like they're
trying to use Einsteinean time-dilation to explain the error, based on the
fact that the GPS satellites are moving about 9000 mph relative to the earth's
surface. But if you work out the numbers, this would only account for a time
error on the order of 5 parts in 1e-10, which is 4-5 orders of mangnitude too
low to account for the error. BTW, the GPS timebase already compensates for
the frequency offsets that are due to both Special Relativity (the speed
difference) and General Relativity (the gravity field difference), and the
fact that both of these vary periodically because of the eccentricity of the
satellite orbits.

One of the problems with your analogy is that one of the tenets of relativity
is that the speed of light is the same for all observers, regardless of
inertial frame. Instead, they observe the photons having different energy
levels (red- or blue-shifted). I don't fully understand all of the nuances,
but it seems to me that this would also imply that a particle like a neutrino
can't exceed the speed of light in any reference frame. I guess the equivalent
of blue-shifting would be a slight increase in the energy of the neutrino. But
do they have the ability to resolve 25ppm differences -- about 400 keV relative
to an intrinsic energy of 16 GeV? The paper doesn't go into a lot of detail,
but it would seem that their abiltiy to measure the energy of a neutrino is
relatively coarse.

One of the big issues as I see it is that it is difficult to define the basic
concept of "simultaneous" in the context of relativity. Observers in different
locations will have different answers. Where exactly is the "observer"
represented by the GPS timebase located? My guess would be that it's at the
center of the earth -- at the origin of the earth-centered inertial (non-
rotating) frame. In which case, most of the effects they're talking about
would mostly cancel out.

Obviously, I don't have any answers here. But based on my limited knowledge
of particle physics, relativity and how GPS works, none of the explanations
offered so far hold water.

-- Dave Twee

2011\10\20@064757 by IVP

face picon face
> think we had a NASA probe go astray years back over the use of
> US Customary vs CGS units in a single calculation

Surely one little miscalculation couldn't be *that* bad could it ?

http://www.telegraph.co.uk/news/uknews/8837736/Man-orders-size-14.5-slipper-and-gets-size-1450-after-mistranslation-in-China.html

2011\10\20@071810 by speff

picon face
Quoting IVP <joecolquittEraseMEspamclear.net.nz>:

>> think we had a NASA probe go astray years back over the use of
>> US Customary vs CGS units in a single calculation
>
> Surely one little miscalculation couldn't be *that* bad could it ?
>
> http://www.telegraph.co.uk/news/uknews/8837736/Man-orders-size-14.5-slipper-and-gets-size-1450-after-mistranslation-in-China.html

That sort of thing happens every day in China, and it's not usually
so funny. It takes a lot of effort to prevent it from happening. 8-(

--sp

2011\10\20@090431 by RussellMc

face picon face
>>> think we had a NASA probe go astray years back over the use of
>>> US Customary vs CGS units in a single calculation
>>
>> Surely one little miscalculation couldn't be *that* bad could it ?

I assume that you know the answer to that.
Apparently affected the braking burn after interplanetary coast, as I recall.
I may recall wrong.
(Or was that main descent retro burn?)

2011\10\20@131020 by Gary Crowell

picon face
en.wikipedia.org/wiki/Mars_Climate_Orbiter

On Thu, Oct 20, 2011 at 7:03 AM, RussellMc <RemoveMEapptechnzEraseMEspamspam_OUTgmail.com> wrote:

{Quote hidden}

>

2011\10\20@140141 by RussellMc

face picon face
> http://en.wikipedia.org/wiki/Mars_Climate_Orbiter

Aye:

The MCO MIB has determined that the root cause for the loss of the MCO
spacecraft was the failure to use metric units in the coding of a
ground software file, “Small Forces,” used in trajectory models.
Specifically, thruster performance data in English units instead of
metric units was used in the software application code titled
SM_FORCES (small forces). The output from the SM_FORCES application
code as required by a MSOP Project Software Interface Specification
(SIS) was to be in metric units of Newtonseconds (N-s). Instead, the
data was reported in English units of pound-seconds (lbf-s). The
Angular Momentum Desaturation (AMD) file contained the output data
from the SM_FORCES software. The SIS, which was not followed, defines
both the format and units of the AMD file generated by ground-based
computers. Subsequent processing of the data from AMD file by the
navigation software algorithm therefore, underestimated the effect on
the spacecraft trajectory by a factor of 4.45, which is the required
conversion factor from force in pounds to Newtons. An erroneous
trajectory was computed using this incorrect data.

Image of result on trajectory here

        http://upload.wikimedia.org/wikipedia/commons/thumb/8/83/Mars_Climate_Orbiter_-_mishap_diagram.png/800px-Mars_Climate_Orbiter_-_mishap_diagram.png

Intended altitude normal to planet for braking was 226 km.
Orbiter was able to survive stresses down to 80 km
but passed within 57 km of planet, or tried to.

Litho-braking is more effective again.


   R


> On Thu, Oct 20, 2011 at 7:03 AM, RussellMc <@spam@apptechnzRemoveMEspamEraseMEgmail.com> wrote:
>
>> >>> think we had a NASA probe go astray years back over the use of
>> >>> US Customary vs CGS units in a single calculation
>> >>
>> >> Surely one little miscalculation couldn't be *that* bad could it ?
>>
>> I assume that you know the answer to that.
>> Apparently affected the braking burn after interplanetary coast, as I
>> recall.
>> I may recall wrong.

2011\10\22@182447 by Gerhard Fiedler

picon face
RussellMc wrote:

>> en.wikipedia.org/wiki/Mars_Climate_Orbiter
>
> Aye:
>
> The MCO MIB has determined that the root cause for the loss of the
> MCO spacecraft was the failure to use metric units in the coding of a
> ground software file, “Small Forces,” used in trajectory models.
> Specifically, thruster performance data in English units instead of
> metric units was used in the software application code titled
> SM_FORCES (small forces).
IMO the biggest problem with the use of traditional (not only English or
US) units is the tendency of people who use them to work with "magic
formulas" and not use proper units with their calculations -- mostly
because they are so used to use those "magic formulas". The idea that
when executing a calculation the units must match (and that therefore
carrying the units along is a quite useful sanity check for the formula)
is something built into SI-like unit systems that is lacking from the
traditional systems.

Gerhard

2011\10\22@183845 by John Gardner

picon face
.... Litho - braking...

:

2011\10\22@190324 by IVP

face picon face

> ... Litho - braking...

...... wireless - braking ....

http://www.popsci.com/technology/article/2011-10/worlds-most-failsafe-wireless-bicycle-brake-could-seed-variety-super-safe-technologies

2011\10\22@191539 by John Gardner

picon face
As long as idiots are allowed to drive, not much point..

2011\10\22@215407 by Herbert Graf

picon face
On Sat, 2011-10-22 at 20:24 -0200, Gerhard Fiedler wrote:
> IMO the biggest problem with the use of traditional (not only English or
> US) units is the tendency of people who use them to work with "magic
> formulas" and not use proper units with their calculations -- mostly
> because they are so used to use those "magic formulas". The idea that
> when executing a calculation the units must match (and that therefore
> carrying the units along is a quite useful sanity check for the formula)
> is something built into SI-like unit systems that is lacking from the
> traditional systems.

Agreed. Many an exam question was corrected by me during an exam by
checking the units and finding something amis. VERY useful sanity check.

TTYL

2011\10\23@002351 by RussellMc

face picon face
Subject line irregardless:

> As long as idiots are allowed to drive, not much point...


But, this is a remotely controlled and controllable brake that does
what it's mean to do to within 3 attempts per trillion.
In the (or, rather, a ) greater order of things it could be very
effective under the non-control of idiots.


2011\10\23@003409 by RussellMc

face picon face
> Agreed. Many an exam question was corrected by me during an exam by
> checking the units and finding something amis. VERY useful sanity check.

As long as one has the courage of one's units.
eg
The unit of effectiveness of a rocket fuel is (arguably) seconds.
(thrust.seconds per mass of fuel).
The unit of fuel consumption of a vehicle is area (ie length^2 =
m^2)(more usually expressed here as l/100km)
or of fuel economy is inverse area = 1 / length^2 or m-2 (usually
expressed as eg mgg).

Force can look like eg kg.m-3.m^2.(m/s)^3 until you cancel wildly to
get kg. m^2. s-3.
It;s only when you decide that f=ma so kg = g.Newton = m.s-2.N that you f=get
kg.m^2.s-3 .N.m.s^-2 = agh ... E&O ...where's the back of an envelope ...


        Russel

2011\10\23@175200 by William \Chops\ Westfield

face picon face

On Oct 22, 2011, at 3:24 PM, Gerhard Fiedler wrote:

> the biggest problem with the use of traditional (not only English or
> US) units is the tendency of people who use them to work with "magic
> formulas" and not use proper units with their calculations

You mean like "to get the length of your dipole antenna, divide 468 by  the frequency"?
(which gives you the length in feet, of course.)  One of the reasons I  never became a ham, sort-of.)
http://www.radioqth.net/AntennaLength.aspx

I like computing with units, except for (theoretically) needing to  know the units of assorted universal constants, which sometimes get  really ugly...

Not terribly happy that even metric has its variations (cgs vs mks vs  si, for instance.)  But at least if you get those wrong, you're likely  to be off by enough that you'd notice...

BillW

2011\10\23@181605 by Chris Roper

picon face
The only Universal Constant is Change :)

It is strange really, I have used metric units my entire life in
school, collage and work, but for some reason I tend to work in both
inches and Meters when it comes to dimensional units.

On 23 October 2011 23:51, William "Chops" Westfield <EraseMEwestfwspam@spam@mac.com> wrote:
{Quote hidden}

>

2011\10\23@183719 by IVP

face picon face
> inches and Meters when it comes to dimensional units.

Back when I used to watch American Chopper, it was frustrating
to see Sr and Jr smoke their brains trying to do maths in 64ths, or
19/16th and a bit minus a touch over 5/8th etc. For goodness sake,
get a ruler with mm ;-

2011\10\23@185556 by William \Chops\ Westfield

face picon face

On Oct 23, 2011, at 3:37 PM, IVP wrote:

> it was frustrating to see Sr and Jr smoke their brains trying to do  
> maths in 64ths, or 19/16th and a bit minus a touch over 5/8th etc.  
> For goodness sake, get a ruler with mm ;-)

That's what calculators are for?

I think if you're dealing lengths on the order of 64ths of an inch, a  ruler with mm isn't going to help much. (1/64 inch ~= 0.4mm; time to  get a micrometer or something instead of a ruler.)

Don't like PCBs.  tenth-inches, mm, mils.  Back and forth.  All the  time.  6mil design rules for .4mm QFPs, 8mils for .5mm QFPs.  Bah!

Back on topic, it's hard to second guess CERN scientists based on  reports in the "popular" press.  One has to assume that they looked  into all the obvious things, or they'd still be thinking instead of  publishing. Has there been a response to the University of Groningen  theory yet?  It seemed simple enough that CERN would have either said  "oh of course" or "no, we already considered that."

BillW

2011\10\23@190401 by John Gardner

picon face
....Back when I used to watch American Chopper...

Once you capiche that 40 thou is just a skoche more than 1 mm,
you're in tall cotton... Good enough for Harleys, that's for sure.

Mixed units have their uses. Or had their uses - If your first few
calculators were made out of wood you probably understand..

2011\10\23@192149 by IVP

face picon face
> That's what calculators are for?

I do remember them using a calculator to work out the percentage
of time that dips*** Mikey was doing any work ;-)

> Has there been a response to the University of Groningen theory yet?

Looked a couple of days ago and AFAICT there've been no update

2011\10\23@192615 by IVP

face picon face
> Has there been a response to the University of Groningen theory yet?

Just had another look

This variation on the original experiment might clear it up

http://www.forbes.com/sites/alexknapp/2011/10/22/opera-collaboration-to-conduct-new-faster-than-light-neutrino-experiment-very-soon/

2011\10\24@031224 by Electron

flavicon
face


At 23.51 2011.10.23, you wrote:
>
>On Oct 22, 2011, at 3:24 PM, Gerhard Fiedler wrote:
>
>> the biggest problem with the use of traditional (not only English or
>> US) units is the tendency of people who use them to work with "magic
>> formulas" and not use proper units with their calculations
>
>You mean like "to get the length of your dipole antenna, divide 468 by  
>the frequency"?
>(which gives you the length in feet, of course.)  One of the reasons I  
>never became a ham, sort-of.)

I am Italian and recall instead length in meters = 143 / MHz

it's been like fifteen years I didn't hear nor recall this formula. :P



{Quote hidden}

>

2011\10\24@135615 by Dwayne Reid

flavicon
face
At 04:37 PM 10/23/2011, IVP wrote:

>Back when I used to watch American Chopper, it was frustrating
>to see Sr and Jr smoke their brains trying to do maths in 64ths, or
>19/16th and a bit minus a touch over 5/8th etc. For goodness sake,
>get a ruler with mm ;-)

Its hard for us old-timers, though.

Canada officially switched to Metric long after I got out of school, so my formative years were spent using inches, feet, miles, ounces, pounds, etc.

Of course, I had been dabbling with electronics WAY before I became a teenager, so the move to Metric-type calculations (powers of ten, etc) was already second nature for me - all of the electrical and electronic quantities were already Metric when I came along.

Still, though, I start all of my PCB layouts on a 0.10" grid and I do all of my home renovation / woodworking stuff using a tape measure that reads in feet and inches.  Even our lumber stores still sell everything in Imperial units - some 20 or 30 years after Canada's official change to Metric.

Horses for courses, I guess.  Metric units make complete sense to me for all of my electronics stuff.  Feet and inches for everything else is just easier for me - I can visualize what something looks like much easier with Imperial units rather than Metric.

By the way - some of the furniture / cabinet workers that I have known in the past frequently work with accuracy down to about 1/128 inches (a little less than 0.2mm).  I'm used to hearing them talk about measurements like "half-inch minus" or "two and a half inches plus", where the 'minus' or 'plus' means about 1/128".  Those guys would definitely NOT have had a problem reading the old analog-type meters that I still often use.

dwayne

-- Dwayne Reid   <@spam@dwaynerspam_OUTspam.....planet.eon.net>
Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
(780) 489-3199 voice          (780) 487-6397 fax
http://www.trinity-electronics.com
Custom Electronics Design and Manufacturing

2011\10\24@143501 by Carl Denk

flavicon
face


On 10/24/2011 1:56 PM, Dwayne Reid wrote:
>
> Horses for courses, I guess.
Now you are getting to a whole another bunch of the stuff that comes out the end of the equine that goes over the fence last.----- Hands, Furlongs, 1/4 post, etc. :)   :)    :)    :

2011\10\24@220331 by Gerhard Fiedler

picon face
RussellMc wrote:

>> Agreed. Many an exam question was corrected by me during an exam by
>> checking the units and finding something amis. VERY useful sanity check.
>
> As long as one has the courage of one's units.

They usually make actually sense, if you think of it.

> eg
> The unit of effectiveness of a rocket fuel is (arguably) seconds.
> (thrust.seconds per mass of fuel).

Isn't thrust a force? If so: Ns/kg = kg m^2 s^-3 * s / kg = m^2 s^-2 ??

> The unit of fuel consumption of a vehicle is area (ie length^2 =
> m^2)(more usually expressed here as l/100km)

That's the (vertical) area of the fuel strip that the vehicle consumes
while driving, so to speak. 10l/100km = 10e-3/100e3 m^2 = 0.1e-6 m^2 =
0.1 mm^2

Gerhar

2011\10\24@220814 by Gerhard Fiedler

picon face
William "Chops" Westfield wrote:

> On Oct 22, 2011, at 3:24 PM, Gerhard Fiedler wrote:
>
>> the biggest problem with the use of traditional (not only English or
>> US) units is the tendency of people who use them to work with "magic
>> formulas" and not use proper units with their calculations
>
> You mean like "to get the length of your dipole antenna, divide 468 by  
> the frequency"?
> (which gives you the length in feet, of course.)  
.... if you use the right unit for frequency, of course :)

Exactly this. I hate it; it doesn't convey understanding as more
sensible formulas tend to do, and I just can't remember such stuff.

Gerhar

2011\10\24@225657 by RussellMc

face picon face
> > You mean like "to get the length of your dipole antenna, divide 468 by
> > the frequency"? (which gives you the length in feet, of course.)

> ... if you use the right unit for frequency, of course :)

> Exactly this. I hate it; it doesn't convey understanding as more
> sensible formulas tend to do, and I just can't remember such stuff.

I too like my formulae to make sense. This one does once you remove
the rubbish and convert to 'propr units' [tm].

As written it has a velocity factor and/or and end effect allowance,
both of which 'muck it up' .

If instead you use (in real units [tm])

         Wavelength ~= 300 / f                F in Mhz, wavelength in metres

You see (of course): Speed of light ~= 3 x 10^8 m/s poking its head up.
Divide by E6 for Hz: Mhz and the 300 makes perfect sense.
NOW you can remember it.
Now we can convert to arcane units (say feet) and add whatever factors
we see fot and divide by 2 to get  half-wave dipole.

Sanity check.
1 MHz.
1 wavelength = 300/1 = 300 metres.
Hlf wavelength = 150 metres.
150/0.3048 = 492 feet.
The original length is short by a factor of 468/492 = 0.9512 -> say 0.95

So wavelength = f/300 x Kwl

        f in MHz
        length in metres
        Kwl = 0.95 = Murphy, end effect, velocity factor, bank holidays, ...

FWIW this has the (obvious but nice) reciprocal results

MHz  = 300 / Wavelength
&
Wavelength = 300 / MHz



    Russel

2011\10\25@015505 by Sean Breheny

face picon face
I believe that the traditional length in feet = 468/frequency (MHz) is
intentionally shorter than the free space value to get even closer to
the exact practical half-wave wire dipole length. I don't think it is
just velocity factor - the current and voltage distribution on a half
wave dipole are not exact sinusoids and I think that makes a few
percent difference in the optimal length.

Sean


On Mon, Oct 24, 2011 at 10:56 PM, RussellMc <spamBeGoneapptechnzEraseMEspamgmail.com> wrote:
{Quote hidden}

>

2011\10\25@062306 by Gerhard Fiedler

picon face
Gerhard Fiedler wrote:

> RussellMc wrote:
>
>>> Agreed. Many an exam question was corrected by me during an exam by
>>> checking the units and finding something amis. VERY useful sanity check..
>>
>> As long as one has the courage of one's units.
>
> They usually make actually sense, if you think of it.
>
>> eg
>> The unit of effectiveness of a rocket fuel is (arguably) seconds.
>> (thrust.seconds per mass of fuel).
>
> Isn't thrust a force? If so: Ns/kg = kg m^2 s^-3 * s / kg = m^2 s^-2 ??

Oops... brain fart :)
Ns/kg = kg m s^-2 * s / kg = m/s, which probably can be interpreted as
the final velocity to which a unit of mass can accelerate something (no
gravity, no friction, etc.)

>> The unit of fuel consumption of a vehicle is area (ie length^2 =
>> m^2)(more usually expressed here as l/100km)
>
> That's the (vertical) area of the fuel strip that the vehicle consumes
> while driving, so to speak. 10l/100km = 10e-3/100e3 m^2 = 0.1e-6 m^2 =
> 0.1 mm^2
>
> Gerhar

2011\10\25@064003 by Gerhard Fiedler

picon face
RussellMc wrote:

>>> You mean like "to get the length of your dipole antenna, divide 468 by
>>> the frequency"? (which gives you the length in feet, of course.)
>
>> ... if you use the right unit for frequency, of course :)
>
>> Exactly this. I hate it; it doesn't convey understanding as more
>> sensible formulas tend to do, and I just can't remember such stuff.
>
> I too like my formulae to make sense. This one does once you remove
> the rubbish and convert to 'propr units' [tm].

This is exactly the thing. All these "magic formulas" have some sense of
this sort in them, but it's buried, and the "proper units" (plus of
course some understanding of what's going on) help bring it out -- and
the result of this bringing out is usually much more helpful. Not for
any given task, but for life... :)

The SI-like systems basically reduce the "magic numbers" to a few basic
constants (speed of light, charge of an electron, etc.) It's still more
than would be nice, but better than otherwise.

Gerhar

2011\10\25@072430 by RussellMc

face picon face
> >> The unit of effectiveness of a rocket fuel is (arguably) seconds.
> >> (thrust.seconds per mass of fuel).


> > Isn't thrust a force? If so: Ns/kg = kg m^2 s^-3 * s / kg = m^2 s^-2 ??
>
> Oops... brain fart :)
>
> Ns/kg = kg m s^-2 * s / kg = m/s, which probably can be interpreted as
> the final velocity to which a unit of mass can accelerate something (no
> gravity, no friction, etc.)


"seconds" is arrived at by misuce of units, but it's generally
accepted "in the trade".
The measure of goodness of a fuel is how many seconds one unit mass
will deliver one unit of thrust,

So eg
if 1 lb of fuel delivers 300 pound.seconds of thrust
then the "specific impulse"
= Isp = 300 pound.seconds/pound_of_propellant
= 300 seconds.
Right?

Bzzzt.
Wrong.
The "error" comes from the misuse of "pounds" in day to day use in the
imperial system.
In any consistent system of units, in a gravity field of g strength,
F=g.m  (NB F=ma)  where F is in units of force and m is in units of
mass.
Joe man in the street has been encouraged to think that the unit of
fouce is the pound, which is correct, and that the unit of mass is the
pond or pound-mass, which is WRONG. The unit of mass in the fps system
is the slug, with a weight of g pounds or about 32 pounds.

Asking for a slug of tomatoes, or 1/32nd of a slug of tomatoes or
1/64+ of tomatoes goeth not down well with Mr Green the greengrocer.

Along the way the fact that "g" is actually in the equation and has
units has gone unnoticed.
Plus it all in and we get

   s x kgf/kgm = g.kgm /kgm = s.g = s.m.S^-2 = m/s = velocity, as Gerhard said.

       <pse scuse units of kgf etc - clarity sought & probably lost,
s = seconds, m = meter>

This is known as the fuel's "characteristic velocity", is
approximately meaningless while not without meaning , and is a factor
od g greater than the Isp.
BUT in mks units if Isp = 300 (and people don't add "seconds" then
characteristic velocity = 300 x 9.8 ~= 300 x 10= 3000 but in fps units
it's 300 x ~=32 = 9600 f/s

Which is a shame.
Isp is units system independent and also has a very real everyday
meaning in terms of payload and thrust and more, whereas
characteristic velocity charges with system (and value of g) so you
have to know and or quote the units system (or find yourself
lithobraking at the darndest of times).

So, sometimes "bad units" that everyone understands, can be very
useful. Until you arrive near Mars, anyway.



  Russell McMahon

Back to wor

2011\10\25@125406 by Gerhard Fiedler

picon face
RussellMc wrote:

>>>> The unit of effectiveness of a rocket fuel is (arguably) seconds.
>>>> (thrust.seconds per mass of fuel).
>
>>> Isn't thrust a force? If so: Ns/kg = kg m^2 s^-3 * s / kg = m^2 s^-2
>>> ??
>>
>> Oops... brain fart :)
>>
>> Ns/kg = kg m s^-2 * s / kg = m/s, which probably can be interpreted
>> as the final velocity to which a unit of mass can accelerate
>> something (no gravity, no friction, etc.)
>
> "seconds" is arrived at by misuce of units, but it's generally
> accepted "in the trade".
> The measure of goodness of a fuel is how many seconds one unit mass
> will deliver one unit of thrust,

This definition could serve in SI units just as well, and the unit would
be seconds. But the value, of course, would depend on the units of mass
and thrust one uses.

{Quote hidden}

Bzzt. Wrong again, I think :)

Isp as stated by you ("lbf * seconds / lb" where pound-force and pound
cancel themselves out) requires a unit system where g has a value of 1
(in the chosen unit system's acceleration unit). In this case g would be
1 lbf/lb.
(This works of course only if you use lbf/lb as acceleration unit. If
you chose to use ft/s^2, as often the case when using Imperial units, g
doesn't have the value of 1 anymore (~32 ft/s^2) and things get ugly
from there on.)


> ... whereas characteristic velocity charges with system (and value of
> g) so you have to know and or quote the units system
You have to do that with Isp just the same, just that the value of g is
"coded" into the units of force and mass, to be 1.

> So, sometimes "bad units" that everyone understands, can be very
> useful.
The problem may be the "understanding" part. It took a lot of work of
quite a number of quite smart people to come up with a consistent system
of measurements. Using other systems, one is often required to recreate
parts of their work -- with much less time and much less mental
resources, and the corresponding outcome... :)

> Until you arrive near Mars, anyway.

Exactly... Isp does have a hidden g in its value. It's hidden in the
definition of lbf.

Gerhar

2011\10\25@133527 by RussellMc

face picon face
> > Isp is units system independent
>
> Bzzt. Wrong again, I think :)

Often, maybe.
But not this time.

What I meant was that if you abuse the units so that the answer comes
out in "seconds", as "the industry" often does then

*If* 1 lbm of propellant has an Isp of 300 seconds when tested
*then* 1 kgm of it will have an Isp of 300 seconds using the same
(incorrect) reasoning
and 1 gram of it will have an Isp of 300 seconds,
etc.

My point was that by fudging the units they have effectively
eliminated the factor of g and made it essentially unity for this
purpose.
The units do NOT produce "seconds" when properly calculated but the
fudged system is units system independent.

Not something that's of much use in many other cases.


        Russell McMaho

2011\10\25@141103 by Gerhard Fiedler

picon face
RussellMc wrote:

>>> Isp is units system independent
>>
>> Bzzt. Wrong again, I think :)
>
> Often, maybe.
> But not this time.
>
> What I meant was that if you abuse the units so that the answer comes
> out in "seconds", as "the industry" often does then

Not really an abuse IMO, just using certain "convenient" units.

> *If* 1 lbm of propellant has an Isp of 300 seconds when tested
> *then* 1 kgm of it will have an Isp of 300 seconds using the same
> (incorrect) reasoning
> and 1 gram of it will have an Isp of 300 seconds,
> etc.

Understood.

> My point was that by fudging the units they have effectively
> eliminated the factor of g and made it essentially unity for this
> purpose.

Sort of... they didn't eliminate g; they require a unit system where g
has the value of 1.

> The units do NOT produce "seconds" when properly calculated but the
> fudged system is units system independent.

I disagree; IMO it is not units-system independent. It requires force
and mass units specifically selected so that together they produce a g
with the value of 1.
The fact that this (g) is hidden in the formula is IMO a (small, or big)
disaster waiting to happen when using it...

Gerhar


'[OT] Speed-of-light experiments give baffling resu'
2011\11\19@190349 by IVP
face picon face
Go #2

http://www.independent.co.uk/news/science/einsteins-laws-questioned-as-speed-of--light-is-broken-again-6264606.html

Scientists have excluded one of the sources of error that could have
led them to make a mistake when they announced in September that
a beam of sub-atomic particles had travelled a fraction of a second
faster than light

Like the earlier experiment, the test found the neutrinos arrived
at the Italian site some 60 billionths of a second faster than if they
were travelling at light speed

2011\11\20@040451 by Joe P. Farr

flavicon
face
Perhaps the speed of light is wrong.

I don't know much about physics, but has anybody checked that the speed
of light (as we've measured it) is still the same?

Isn't it possible that either the speed we have is wrong (equipment and
measuring techniques must be improving all the time), or, something in
the universe (or at least our small part of it) has changed and the
speed of light has/is changing ?



{Original Message removed}

2011\11\20@062440 by RussellMc

face picon face
That must be an extremely high energy source they are using.
Neutrons capable of this you'd not want to meet :-).

         They repeated the first experiment, in which they had fired
pulses of neutrons
         from the Cern underground laboratory near Geneva through
solid rock to subterranean
         particle detectors at the Gran Sasso National Laboratory in
Italy about 750km (466 miles) away.


OR the proof reader was travelling at far slower than the speed of write.



                            Russel


'[OT] Speed-of-light experiments give baffling resu'
2012\02\23@175851 by IVP
face picon face
www.dailymail.co.uk/sciencetech/article-2105353/Faulty-wires-CERN-test-results-debunked-Einsteins-theory-relativity.html

It is now believed that the surprising result was down to a loose fibre
optic cable linking a Global Positioning System satellite receiver to a
computer

Gillies confirmed that a flaw in the GPS system was now suspected
as a possible cause for the surprising reading. Further testing was
needed before any definite conclusions could be reached, he added

More... (looser matching)
- Last day of these posts
- In 2012 , 2013 only
- Today
- New search...